From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751794AbdK0J5x (ORCPT ); Mon, 27 Nov 2017 04:57:53 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:34675 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751777AbdK0J5w (ORCPT ); Mon, 27 Nov 2017 04:57:52 -0500 Date: Mon, 27 Nov 2017 10:57:37 +0100 From: Peter Zijlstra To: Thomas Gleixner Cc: LKML , Dave Hansen , Andy Lutomirski , Ingo Molnar , Borislav Petkov , Brian Gerst , Denys Vlasenko , "H. Peter Anvin" , Josh Poimboeuf , Linus Torvalds , Rik van Riel , daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, linux-mm@kvack.org, michael.schwarz@iaik.tugraz.at, moritz.lipp@iaik.tugraz.at, richard.fellner@student.tugraz.at Subject: Re: [patch V2 1/5] x86/kaiser: Respect disabled CPU features Message-ID: <20171127095737.ocolhqaxsaboycwa@hirez.programming.kicks-ass.net> References: <20171126231403.657575796@linutronix.de> <20171126232414.313869499@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171126232414.313869499@linutronix.de> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 27, 2017 at 12:14:04AM +0100, Thomas Gleixner wrote: > PAGE_NX and PAGE_GLOBAL might be not supported or disabled on the command > line, but KAISER sets them unconditionally. So KAISER is x86_64 only, right? AFAIK there is no x86_64 without NX support. So would it not make sense to mandate NX for KAISER?, that is instead of making "noexec" + KAISER work, make "noexec" kill KAISER + emit a warning. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 86C7F6B0033 for ; Mon, 27 Nov 2017 04:57:46 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id g29so7916777pfk.4 for ; Mon, 27 Nov 2017 01:57:46 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [65.50.211.133]) by mx.google.com with ESMTPS id x4si22545642plw.539.2017.11.27.01.57.45 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Nov 2017 01:57:45 -0800 (PST) Date: Mon, 27 Nov 2017 10:57:37 +0100 From: Peter Zijlstra Subject: Re: [patch V2 1/5] x86/kaiser: Respect disabled CPU features Message-ID: <20171127095737.ocolhqaxsaboycwa@hirez.programming.kicks-ass.net> References: <20171126231403.657575796@linutronix.de> <20171126232414.313869499@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171126232414.313869499@linutronix.de> Sender: owner-linux-mm@kvack.org List-ID: To: Thomas Gleixner Cc: LKML , Dave Hansen , Andy Lutomirski , Ingo Molnar , Borislav Petkov , Brian Gerst , Denys Vlasenko , "H. Peter Anvin" , Josh Poimboeuf , Linus Torvalds , Rik van Riel , daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, linux-mm@kvack.org, michael.schwarz@iaik.tugraz.at, moritz.lipp@iaik.tugraz.at, richard.fellner@student.tugraz.at On Mon, Nov 27, 2017 at 12:14:04AM +0100, Thomas Gleixner wrote: > PAGE_NX and PAGE_GLOBAL might be not supported or disabled on the command > line, but KAISER sets them unconditionally. So KAISER is x86_64 only, right? AFAIK there is no x86_64 without NX support. So would it not make sense to mandate NX for KAISER?, that is instead of making "noexec" + KAISER work, make "noexec" kill KAISER + emit a warning. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org